Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows provided by (used in) operating activities:
Net income	$ 123,539	$ 129,655
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	129,734	110,280
Rationalization charges	4,485	13,929
Stock compensation expense	11,052	9,724
Loss on early extinguishment of debt	7,052	0
Other changes that provided (used) cash, net of effects from acquisition:
Trade accounts receivable, net	(285,901)	(231,674)
Inventories	(2,895)	(6,546)
Trade accounts payable	1,725	(60,423)
Accrued liabilities	16,003	34,371
Other, net	(9,247)	(10,885)
Net cash used in operating activities	(4,453)	(11,569)
Cash flows provided by (used in) investing activities:
Purchase of business, net of cash acquired	(1,028,729)	0
Capital expenditures	(124,163)	(151,522)
Proceeds from asset sales	539	8,926
Net cash used in investing activities	(1,152,353)	(142,596)
Cash flows provided by (used in) financing activities:
Borrowings under revolving loans	1,108,208	601,558
Repayments under revolving loans	(680,986)	(303,259)
Proceeds from issuance of long-term debt	1,789,200	0
Repayments of long-term debt	(755,037)	(7,775)
Changes in outstanding checks - principally vendors	(78,944)	(101,765)
Dividends paid on common stock	(30,373)	(31,344)
Debt issuance costs	(16,643)	0
Repurchase of common stock	(4,123)	(9,634)
Net cash provided by financing activities	1,331,302	147,781
Cash and cash equivalents:
Net increase (decrease)	174,496	(6,384)
Balance at beginning of year	24,690	99,945
Balance at end of period	199,186	93,561
Interest paid, net	78,528	46,899
Income taxes paid, net	$ 50,226	$ 46,206